The player missed Saturday’s 5-2 victory over West Ham due to the issue. The 22-year-old German playmaker has enjoyed a strong second half of the season, scoring four goals and providing two assists in six January games.
However, he was forced out of the squad for the win against Nottingham Forest after picking up an injury during the pre-match warm-up.
"I think that will be too early, but I said last week I didn’t expect him not to be available for today, so sometimes with an injury things can develop in a positive way or in a negative way,” said Slot.
“Now we are thinking it doesn’t have to take too long, but Tuesday will probably be too early. The week after will be tight as things stand now, but as I said, I thought that he would be available for today as well, which didn’t happen unfortunately."